Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
29 Cards in this Set
- Front
- Back
|
What is the agent of plague
|
Yersinia pestis
|
|
|
What is the agent of Brucellosis
|
Brucella species
|
|
|
What is the agent of tularemia
|
Francisella tularensis
|
|
|
What kind of bacteria are Yersinia pestis, Brucella spp, and Francisella tularensis
|
Gram negative rods that cause systemic, zoonotic infections
|
|
|
What are the three types of plague caused by Yersinia pestis
|
Bubonic
Pneumonic Septicemic Humans are incidental in the rodent-flea cycle |
|
|
What are the general characteristics of Yersinia pestis
|
Gram negative coccobacillus with bipolar staining
Facultative intracellular that grows within the phagolysosomes of macrophages Not fastidious, optimal growth 28C, but virulence traits expresses at 37C |
|
|
How do humans become infected with Yersinia pestis
|
Sylvatic transmission with chipmunks, praire dogs, and squirrels. Most common
Urban plague (rat to flea) |
|
|
What disease presents with high fever, tachycardia, malaise, aching of extremities, and painful bubo (tender, enlarged lymph node)
|
Bubonic plague. Most untreated patients progress to bacteremia and die of Gram-negative septic shock soon after developing bubo
|
|
|
What disease presents only with fever, malaise, and a feeling of tightness in the chest. Productive cough, dyspnea, and cyanosis develop later
|
Pneumonic plague. Develops in a few with bubonic plague as a secondary pneumonia caused by bacteremic spread to the lungs. Human to human can occur. Can't survive without therapy
|
|
|
Transmission of Yersinia pestis is enhanced by what
|
Hemin storage locus (hms) gene, which encodes a factor that causes blockage in the foregut of the flea
|
|
|
What are the virulence factors of Yersinia pestis
|
Capsular antigen (fraction 1): antiphagocytic
V antigen: plasmid encoded. Induced by low calcium levels Yersinia outer membrane proteins (YOPs): plasmid encoded, inhibits phagocytosis by macrophages |
|
|
How is Yersinia pestis treated
|
Streptomycin and tetracycline. Vaccine also available
|
|
|
What is Brucellosis
|
Disease of domestic animals, never human to human. Propensity to localize in pregnant uterus and mammary glands. Growth factor erythritol
|
|
|
What are the characteristics of Brucella
|
Slow-growing, fastidious gram negative rods. Facultative intracellular parasites of the RES. Cause chronic infections
|
|
|
What species of Brucella cause disease in humans
|
B. melitensis (goats)
B. abortus (cattle) B. suis (swine) |
|
|
How are Brucella species differentiated
|
Whether they need CO2 for growth (B. abortus), inhibition of growth, slide agglutination
|
|
|
What causes Malta fever
|
Brucella melitensis
|
|
|
How is Brucella transmitted to humans
|
Eye, nasopharynx, skin, or cut after contact
|
|
|
What are the complications of Brucella infection
|
Arthritis is the most common; reproductive tract infections (epididymitis, orchitis, and abortion)
|
|
|
What type of immunity is protective against Brucellae
|
Cell-mediated immunity
|
|
|
How is Brucella treated
|
Intracellular organism, so doxycycline and rifampin. Vaccines for animals exist
|
|
|
What causes Tularemia
|
Infection with Francisella tularensis
|
|
|
What are the characteristics of Francisella
|
Gram negative coccobacilli, fastidious, grows slowly.
Facultative intracellular for macrophages Very low infectious dose. Point of entry may not be apparent |
|
|
Tularemia, caused by Francisella tularensis, can manifest as what
|
Skin lesions, pneumonic, gastrointestinal, ocular, and systemic
|
|
|
How is Tularemia, caused by Francisella tularensis, acquired
|
Direct contact with infected animals or bites of infected insects
|
|
|
What are the four major clinical manifestations of Francisella infection
|
Ulceroglandular: follows primary infection of skin. Fever, headache, malaise, bubo
Pneumonic: aerosols Typhoidal: ingestion; typhoidal-like illness Oculoglandular: contaminated eye with infected material |
|
|
How is Francisella acquired
|
Direct contact with infect animals (hunter, vets) or bites of infected insects
|
|
|
What specific media is needed to culture Francisella
|
Cysteine-enriched. Lab must be alerted of potential diagnosis
|
|
|
What type of immunity is important for Francisella infection
|
Cell-mediated immunity. Vaccine availabe
|
